[clang][analysis][NFC]place the comment to correct position (#117467)

Author: HerrCai0907

clang/lib/Analysis/ExprMutationAnalyzer.cpp

@@ -231,11 +231,11 @@ ExprMutationAnalyzer::Analyzer::findPointeeMutation(const Decl *Dec) {
 const Stmt *ExprMutationAnalyzer::Analyzer::findMutationMemoized(
     const Expr *Exp, llvm::ArrayRef<MutationFinder> Finders,
     Memoized::ResultMap &MemoizedResults) {
+  // Assume Exp is not mutated before analyzing Exp.
   auto [Memoized, Inserted] = MemoizedResults.try_emplace(Exp);
   if (!Inserted)
     return Memoized->second;
 
-  // Assume Exp is not mutated before analyzing Exp.
   if (isUnevaluated(Exp))
     return nullptr;